1. Field of the Invention
This invention relates to alkane sulfonic acids in cleaning preparations and/or disinfectants, more especially in the food-processing industry.
2. Statement of Related Art
In the field of cleaning and disinfection, products based on nitric acid, sulfuric acid and phosphoric acid are at present used for all applications where acidic preparations are indicated. Mixtures of these acids are also used for special applications. Hydrochloric acid and hydrofluoric acid are only used in particular cases where the material to be cleaned is not endangered by corrosion.
Accordingly, only the first three mineral acids set forth above are used for cleaning and disinfection in the food-processing industry. Besides its function as an acid, phosphoric acid in particular shows cleaning active effects. Accordingly, it is used to a predominant extent in the field of cleaning and disinfection.
The list of acids should be completed by a number of organic acids, particularly amidosulfonic acid, formic acid, in some cases acetic acid, and citric acid. On account of their weaker acidity, however, they cannot be universally used. The corresponding acidic salts of the above inorganic and organic acids are of course also used. Phosphoric acid and its acidic salts are still being used to a predominant extent as the basis for acidic cleaning preparations and/or disinfectants. The phosphoric acid or its salts are combined with surfactants, foam inhibitors, corrosion inhibitors and, optionally, solution promoters, and also with special disinfection components which are stable and active in the phosphoric acid medium, for example quaternary ammonium compounds, elemental iodine, hydrogen peroxide and other per compounds.
These combinations are used at temperatures of from 5.degree. to 85.degree. C. to remove protein, fat and mineral soil of the type encountered in the corresponding branches of the food-processing industry. Products based on sulfuric acid and nitric acid are also commercially available for removing soil of a purely mineral nature. Sulfuric and nitric acid may also be combined with special disinfection components which are stable and active therein.
Due to the recently increasing need to replace nitrate-containing and, generally, nitrogen-containing products and especially products based on phosphoric acid by other acid bases for environmental reasons, a number of basic studies has shown that only limited possibilities are available for replacing either nitric acid or phosphoric acid. Sulfuric acid for example, which might be considered as a replacement, cannot be used for removing such soil as, for example, carbohydrates, protein, fats, inorganic material constituents and other residues due to its inadequate cleaning effect with respect to organic soil. In addition, sulfuric acid has a highly corrosive effect on chrome-nickel steels and aluminium surfaces, particularly at relatively high temperatures of around 85.degree. C.
One possible solution to this problem is the use of amidosulfonic acid, which has a good cleaning effect with respect to organic soil and which, in terms of corrosion, is acceptable for chrome nickel steel and aluminium.
In so-called standing baths, i.e. cleaning baths of the type predominantly used for repeatedly carrying out a cleaning and/or disinfection process, amidosulfonic acid undergoes decomposition. The cleaning effect then becomes inadequate and, in addition, corrosion occurs. In most cases, the organic acids known from the prior art are ineffectual, particularly with respect to inorganic soil (short-chain carboxylic acids and dicarboxylic acids), or have too strong an odor during the cleaning process (formic acid).
Ullmanns Encyklopadie der technischen Chemie, 4th Edition, Vol. 20, pages 153 et seq. describes cleaning preparations and disinfectants for the food industry and lists the constituents typical of such preparations.